The new, higher rating - the third-highest on Moody's scale for corporate bonds - has a stable outlook, according to the rating agency.
The upgrade reflects TSMC's dominant position in the semiconductor industry, particularly in key components for cutting-edge technology. Moody's also points to strong leadership, stable production facilities and a diverse customer base.
TSMC's low debt-to-equity ratio and strong cash flow are also factors behind the higher rating, according to Moody's.
